1. Field of the Invention
The invention relates to a cycloidal propeller.
2. Description of the Related Art
Cycloidal propellers serve mostly as marine major drives, but may be used also as auxiliary drives, namely whenever especially high maneuverability is required. One type of cycloidal propeller is described in Voith document reprint 9.94 2000. The wing mechanism disclosed therein serves to move the wings on the wing circle of the rotor in the necessary positions to generate propelling forces, and also to control forces. Feathering is effected by way of a central joystick, which is actuated by two servomotors arranged at right angles to one another. The rotor is generally powered via a diesel engine with a gear drive comprising a bevel ring gear and a bevel pinion.
DE-B 19 41 652 describes a cycloidal propeller serving only as a marine auxiliary drive and which at cruising speed of the ship, is operated exclusively as a rudder. Feathering of the individual wings is effected by suitable accessory apparatuses to a degree such that in the so-called nonbuoyant, i.e., nonpropelling sailing position, they are parallel to one another and can in this position be adjusted to the necessary angular position by rotation of the rotor element according to the required rotor position.
DE 36 06 549 A1 describes a system to generate motion, or also drive, which in the broadest sense could be described also as a cycloidal propeller with multiple-part wings, i.e., composite wing profile. Gear wheels are primarily used as an actuating drive for the wing components, and for one the rear wing part, in the last part of the drive train formed of a chain of gear/wheels, consists of a gear segment and a gear wheel mounted on the shaft end of the rear wing part.
DE-AS 11 92 945 is geared to safety against wing damage by foreign objects and provides safety valves for relieving the pressure spaces of the drive servomotors in case external forces exerted on the wings by foreign objects would cause an unallowable pressure increase in the pressure spaces.
In the case of the cycloidal propeller described in the not prepublished older document DE 196 02 043 C1, a large actuation option of the wing is achieved by a gear drive fitted between the linkages of the wing mechanism and the respective wing shaft consisting predominantly of a gear segment and a gear wheel.
But the design of the cycloidal propeller, notably concerning the configuration of the propeller mechanism and attachment to the wing shaft, results in relatively short feathering paths of the wings. Therefore, it is not possible to bring the rounded head end of the wings in a forward direction of travel. Therefore, wing profiles are used that deviate from the usual shape and have an essentially oval shape. At certain states of travel this is unfavorable, for example when the ship travels within narrow channels, in harbors or in the skerries. In such states of travel, it is advantageous to drive the ship using the cycloidal propeller, and not the main drive, which is configured for a considerably higher speed. The high maneuverability of the cycloidal propeller is utilized here.